A few users have reported unexpected behavior when using Chrome 12 on ONLY the Apple Mac operating system. The behavior ranges from not being able to click a shape, to only being able to select shapes and not deselect them. Although this behavior seems random, we've been able to track this down to one root cause where we believe that Flash thinks the SHIFT key is being pressed (key down event) and never depressed (key up event). We believe this is a software bug in the communication of events between Chrome and the embedded Flash player. We've got a small sample test case in the video below, clearly showing this bad behavior:
We have posted a bug report to Google as well. You can track the issue here: http://code.google.com/p/chromium/issues/detail?id=86992
If you run into this issue, the workaround right now is to either click away from the application, or to hit the SHIFT key again.
In the meantime, we'll see if we can find a more viable workaround to alleviate the issue in the short term.